What happened
On January 4, 2013, a Cessna 172N, registration F-OPLC, departed from Saint-Barthélemy airport for a local instructional flight. The crew consisted of an experienced instructor pilot and a student undergoing initial training. During the return portion of the flight, the instructor took control of the aircraft to perform a landing on runway 10.
As the aircraft approached the La Tourmente pass, it encountered sudden and severe turbulence. The pilot reported that despite increasing the approach speed by 5 knots to compensate for the weather, a sudden gust from the rear right caused the aircraft to yaw violently to the right and then to the left. Despite applying full takeoff power in an attempt to execute a go-around, the aircraft was pushed 90 degrees off the approach axis with a significant vertical descent. The aircraft struck the ground near the northern edge of the pass. The pilot sustained injuries, while the student was able to assist in evacuating the wreckage. The aircraft was destroyed.
The investigation
Investigators examined the wreckage and found no technical anomalies or mechanical failures that could explain the accident. Meteorological data from the aerodrome station confirmed that at the time of the accident, winds were sustained at 19 knots from 060°, with gusts reaching up to 23 knots. Other aircraft operating at the field that day also encountered significant turbulence, with some pilots being forced to execute go-arounds.
The investigation also noted that the pilot, a highly seasoned instructor with nearly 20,000 flight hours and extensive experience at Saint-Barthélemy, was wearing only a lap belt rather than a shoulder harness to allow for greater mobility during instruction. This lack of a diagonal restraint was noted in relation to the nature of the pilot's injuries.